Reservoir containing means for heating congealable liquids



March 8, 1955 F. E. CARROLL, JR

RESERVOIR CONTAINING MEANS FOR HEATING CONGEALABLE LIQUIDS 2 Sheds-Sheet 1 Filed Nov. 25, 1953 ATTORNE March 8, 1955 F. E. CARROLL, JR

RESERVOIR CONTAINING MEANS FOR HEATING CONGEALABLE LIQUIDS Filed Nov. 25, I953 2 Sheets-Sheet 2 INVENTOR fiP/mm 5. GKKOAA J71 ATTORNEY United States Patent RESERVOIR CONTAINING MEANS FOR HEATING CONGEALABLE LIQUIDS Frank E. Carroll, Jr., Dayton, Ohio, assignor to United Aircraft Products, Inc., Dayton, Ohio, a corporation of Ohio Application November 25, 1953, Serial No. 394,366

13 Claims. (Cl. 257-201) This invention relates to tanks used in engine oil circulating systems of aircraft and the like to hold or to store the make-up oil.

An object of the invention is to make such tanks more consistent in their operation under cold weather conditions.

Another object of the invention is to insure a continuous flow of oil. in the system when the oil in the tank is congealed, but particularly when it is only partly congealed.

A further object of the invention is to obviate clogging of the tank outlet by masses of melting or partly congealed oil.

Still another object of the invention is to present a generally new combination of oil tank and hopper in which the hopper and elements on the hopper perform a function in establishing and maintaining a fiow path to the tank outlet.

Other objects and structural details of the invention will appear from the following description when read in connection with the accompanying drawings, wherein:

Fig. l is a view in front elevation of a hopper embodied in the combination of the invention in its illustrated form;

Fig. 2 is a view in perspective of the hopper of Fig. 1;

Fig. 3 is a diagrammatic view of parts of an engine oil circulating system, including a storage tank in accordance with the illustrated embodiment of the invention; and

Fig. 4 is a view in cross section, taken substantially along the line 44 of Fig. 3.

Referring to the drawings, the principal element of the combination of the present invention is the hopper assembly. As shown in Figs. 1 and 2, in the illustrated embodiment of the invention, such assembly comprises a cylindrical shell having an expansion or overflow tank 11 at its upper end, such tank being in this instance oifset for connection to a vent misaligned with respect to the shell 10. The bottom of the shell 10 is closed by a cap 12 having a circumferential series of approximately radial fins 13. Hollow coupling members 14 and 15 are installed in the cap 12 and serve respectively as the inlet to and outlet from the hopper.

Mounted lengthwise of the hopper, outside the shell 10, is a pair of baflles 16 and 17 inclining toward one another but terminating short of convergence whereby to form a longitudinal slot 18, bridged at longitudinally spaced points by supports 19. At their lower ends, as viewed in Fig. 1, the baflles 16 and 17 project below the edge of the cap 12 and terminate in a closure plate 21 extending toward the axis of the hopper and having also upturned portions 22 connected as by welding to the bafiles 16 and 17 and to the cap 12. The projecting portions of the bafiles 16 and 17, the plate 21 and portions 22 in efiect define a trough or spout arranged for discharge toward the axis of the hopper into the area occupied by the fins 13. In the illustrated embodiment of the invention, the fins 13 are arranged in a relatively short arcuate series, situated to radiate from the center of the cap 12 to or toward the mouth of the aforementioned trough or spout.

The baflles 16 and 17, together with the wall of the shell 10, the bottom plate 21 and portions 22 define a chamber or flow passage 23 having restricted communication with the exterior by way of slot 18. The upper end of the passage 23 is open.

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A pipe 24 is connected to the shell 10 for filling of the hopper.

It will be understood that the hopper assembly as described is constructed and arranged for installation in a larger tank shell, holding the main body of make-up oil in an engine oil circulating system. The hopper may, for example, be constructed and arranged as the hopper assembly of H. T. Booth application, S. N. 350,295, filed April 22, 1953, for Reservoir for Congeable Liquid, and for mounting in an engine oil system as disclosed in that application.

Thus, and referring to Figs. 3 and 4, the hopper is received in a larger shell or tank 25 containing a main body 26 of oil. Mounted on the underside of the tank 25 is a valve assembly 27 controlling the movements of the oil into and out of the tank and hopper. Separate conduits 28 and 29 connect the valve assembly 27 to an engine 31, the former conducting oil from the engine to the valve assembly and the latter returning oil to the engine. Oil flowing to the valve assembly is directed alternatively (according to a principle of flow diversion) to the aforementioned hopper inlet 14 and to a stand pipe 32 which extends through the plate 21 and rises in the flow passage 23, the upper end of the pipe 32 being bent over and discharging into the tank 25. In the act of flow diverting the oil will for a period he directed simultaneously to the hopper inlet 14 and to the stand pipe 32. Oil returning to the engine flows out of the hopper by way of the aforementioned hopper outlet 15 and out of the tank by way of an outlet 33 in the bottom of the tank. The tank outlet 33, as indicated, is situated beneath the hopper, in the area of the fins 13 and in adjacent relation to the discharge end of the passage 23.

While the hopper may assume a variety of forms within the scope of the invention, it is in the illustrated instance of the double wall type, there being an inner shell 34 spaced from the shell 10 a distance defining an annular passage 35. The hopper outlet 15 is connected to the bottom of inner shell 34. The hopper inlet 14 is connected to the space between the shells 10 and 34 or passage 35. Oil flowing to the hopper rises in the passage 35, spills over into the open top of the shell 34 and then descends toward the outlet 15.

In the operation of the system the oil rising in the passage 35 is heated by reason of its movement through the engine. Some of this heat is absorbed by the shell 10 which thus presents a warm or heated surface to the surrounding oil in the tank 25. If the oil in the tank is congealed, the heat so applied tends to open a fluid path in the tank extending in touching, longitudinal relation to the shell 10 toward the tank outlet 33. Thus when the oil flow is diverted from the hopper inlet 14 to the tank inlet 32, the tank is conditioned to receive such flow and to supply an adequate volume of oil to the system through the outlet 33.

If the oil in the tank 25 is only partly congealed, it tends, under applied heat and as a result of diverting, to break down into soft, relatively impermeable masses which slide to the bottom of the tank where they may clog the outlet 33 and so interfere with a free circulation of oil. According to the present invention, however, the outlet 33 is protected by the closure plate 21, aided by the fins 13, which cooperate with the bottom of the tank in excluding masses of non-fluid oil from the outlet. Further, the outlet is, in a decongealing period of operation supplied by way of the passage 23. The baflles 16 and 17, plate 21 and portions 22 which bound and define the passage 23 also exclude non-fluid masses, but permit fluid oil freely to enter the passage 23 through the slot 18. A continuously open path extending lengthwise of the hopper to the outlet 33 therebyis maintained for fluid oil.

A cold engine start normally will find the oil standing in tank inlet pipe 32 also congealed. The location of this pipe in passage 23 insures that a path through the passage will be open at the time of diverting since the oil in the pipe is required to be thawed by heat conducted through the surrounding oil in passage 23. While the invention has been disclosed in connection with a doublewall hopper, it will be understood that it is equally applicable to one of single wall construction.

Further, the fins 13 since they project from the hopper, serve as heat transfer means by which congealed or partly congealed oil in the region of the outlet 33 may more quickly be made fluid. Being in the illustrated instance made in the main of sheet metal, parts of the hopper assembly may be formed with strengthening beads. Triangular ribs 36 may, for example, be provided on the bottom of the cap 12 for this purpose, as shown in Fig. 2.

The constrction and mode of operation of the valve assembly 27 forms no part of the present invention. For purposes of illustration, however, such assembly is here indicated as comprising a slide type valve 36 having a circumferential slot 37 and adjusted in an axial sense by a thermally responsive bellows 38 in the path of oil returning to the engine. In the operation of the system as equipped with the illustrative valve assembly, when the oil is cold flow is to the hopper by way of pipe 14 and flow out of the tank assembly is by way of the hopper outlet pipe 15. A warming influence on the element 38 opens the pipe 32 and the pipe 33 to flow and ultimately closes pipe 14. It is not intended that the disclosed valve should be in any way limitative on the instant tank structure which it is considered has an identity apart from any valve or valves which might be used in connection therewith.

What is claimed is:

1. An oil tank for use in an engine oil circulating system, including an outer tank holding the main body of oil, a hopper in said tank through which a portion of the oil in the system is circulated in segregated relation to the main body of oil in the tank, an outlet from the bottom of said hopper through said tank, an outlet in the bottom of said tank, and means defining a partly confined path to said last named outlet through the oil in said tank and in adjacent, external relation to said hopper.

2. A storage tank for use in an engine lubricant circulating system, including an outer tank shell having an outlet opening in the bottom thereof, a hopper in said tank shell in overlying relation to said outlet opening through which a portion of the lubricant in the system may be circulated in segregated relation to the main body of lubricant in the tank shell, in the operation of the system said hopper presenting a heated surface to lubricant in said tank shell, and means defining a partly confined path downwardly along the exterior of said hopper toward said outlet opening.

3. A storage tank according to claim 2, characterized by fins on the bottom of said hopper extending toward said opening and continuing said path.

4. A storage tank for use in an engine lubricant circulating system, including an outer tank shell holding the main body of stored lubricant, an outlet opening in the bottom of said tank shell, a hopper in said tank shell through which a portion of the lubricant in said system may be circulated in segregated relation to the main body thereof, said hopper being in overlying relation to said outlet opening, and fins on the bottom of said hopper restricting and directing flow to said outlet opening.

5. The combination, in an oil tank for use in an engine oil circulating system, of a hopper, bafile means extending lengthwise of said hopper and defining a passage having restricted communication with the space exteriorly of the hopper, and an outer tank shell receiving said hopper therein and having an outlet opening in the bottom beneath said hopper, said baflle means admitting decongealed oil from the outer tank shell to said passage and said passage discharging such oil to said outlet opening, said baffie means inhibiting clogging of said outlet opening by partly congealed oil.

6. The combination, in an oil tank for use in an engine oil circulating system, of a hopper, baffle means extending lengthwise along the side of said hopper and defining a passage having restricted communication with the space exteriorly of the hopper, an outer tank shell receiving said hopper therein and having an outlet opening, and a spout at the bottom of said passage delivering oil from said passage to said outlet opening, said bafile means admitting decongealed oil to said passage from said outer tank shell, while restricting access of partly congealed oil to said outlet means.

7. The combination, in an oil tank for use in an engine oil circulating system, of a hopper, baflle means mounted on the outside of said hopper and extending lengthwise thereof, other approximately radial bafile means on the bottom of said hopper, and an outer tank 5. 1911 receiving said hopper and having an outlet opening in the bottom beneath said hopper, said bafile means cooperating with one another and with the bottom of the tank shell to admit fluid oil to said outlet opening while inhibiting the movement of congealed and partly congealed oil thereto.

8. The combination, in an oil tank for use in an engine oil circulating system, of a hopper, converging baffie members mounted on the outside of said hopper and extending lengthwise thereof, said baflles defining with said hopper a longitudinal passage having restricted communication with the exterior of the hopper over substantially the full length of said passage, a spout at the bottom of said baffles directing oil descending in said passage beneath said hopper toward the axis thereof, approximately radial fins on the bottom of said hopper, and an outer tank shell receiving said hopper and having an outlet opening in the bottom beneath said hopper, said outlet opening being suplied with fluid oil from the tank by way of said passage and said spout while said bafiies and said fins inhibit movement of congealed and partly congealed oil to said outlet opening.

9. A combination according to claim 8, characterized by an inlet to said tank including a stand pipe rising through said passage.

10. The combination, in an oil tank for use in an engine oil circulating system, of a hopper, an outer tank shell receiving said hopper, said shell having a bottom wall and said hopper standing upright in said shell with its lower end in spaced apart adjacent relation to said bottom wall, an outlet from said tank in said bottom wall beneath said hopper, and heat transfer fins on the lower end of said hopper projecting toward said outlet.

11. In a storage tank of an engine lubrication system, a hopper adapted to be vertically positioned in said tank to provide a flow path for heated oil in heat exchange relation with a main body of oil in said tank, said hopper comprising nested closely spaced inner and outer containers that cooperate to define a narrow path for fiow of oil therebetween, said outer container being provided at its bottom with an inlet connection communicating with said narrow path and said inner container being pro vided near the center of its bottom with a discharge connection communicating with the interior of said inner container and extending through the bottom of said outer container, baffle means mounted on the exterior of said outer container and defining a channel extending from a point near the top of said hopper to the bottom of said hopper and then inwardly along said bottom to a point near said discharge connection, whereby oil entering said channel is caused to flow in heat exchange relation with respect to oil in said hopper.

12. In a storage tank of an engine lubrication system, a hopper adapted to be vertically positioned in said tank to provide a flow path for heated oil in heat exchange relation with a main body of oil in said tank, said hopper comprising nested closely spaced inner and outer containers that cooperate to define an annular path for flow of oil therebetween, said outer container being provided at its bottom with an inlet connection communicating with said annular path and said inner container being provided near the center of its bottom with a discharge connection communicating with the interior of said inner container and extending through the bottom of said outer container, a pair of baffles mounted on the exterior of said outer container and extending outwardly therefrom, said baffles extending length-wise substantially in parallel from a point near the top of said hopper to the bottom of said hopper and then inwardly along said bottom to a point near said discharge connection, said bafiles cooperating with the exterior Wall of said outer container to define a partially enclosed channel, whereby oil entering said channel is caused to flow in heat exchange relation with respect to oil in said hopper.

13. In a storage tank of an engine lubrication system, a hopper adapted to be vertically positioned in said tank to provide a flow path for heated oil in heat exchange relation with a main body of oil in said tank, said hopper comprising nested closely spaced inner and outer containers that cooperate to define an annular path for flow of oil therebetween, said outer container being provided at its bottom with an inlet connection communicating with said annular path and said inner container being provided near the center of its bottom with a discharge connection communicating With the interior of said inner container, a pair of baflles mounted on the exterior of said outer container and extending outwardly therefrom, said baffles extending length-wise substantially in parallel from a point near the top of said hopper to the bottom of said hopper and then inwardly along said bottom to a point near said discharge connection, said bafiles cooperating with the exterior wall of said outer container to define a partially enclosed channel whereby oil entering said channel is caused to flow in heat exchange relation with respect to oil in said hopper, and an oil conduit positioned in said channel, said conduit being adapted when 'said hopper is operatively positioned in said tank 5 nular path.

References Cited in the file of this patent UNITED STATES PATENTS Stockdale Feb. 15, 1938 

